1. Field of the Invention
The present invention relates to a method for inserting an implant into a living tissue. Particularly, the present invention relates to a method of suitably inserting a dental implant in a jawbone.
2. Description of the Related Art
A procedure to insert an implant in a jawbone will be described using a dental implant treatment as an example. First, a cavity is disposed in a jawbone of a portion where a tooth is missing. Then, in the cavity, an implant (also referred to as an artificial dental root or implant fixture) is inserted. Then, at an end portion of the implant in a state adhering to the jawbone, abutment is attached. Moreover, a super-structural prosthesis (artificial tooth) such as ceramic crown is fixed on the abutment, and the treatment is completed.
In the past, a drill for chipping a jawbone has been widely used as a tool for providing a cavity. Also, a bone chisel forming a cavity by being hammered in has been widely used. However, there are several problems in the method of forming the cavity using these tools. The first problem is that if a cavity is to be formed using these tools, full cure requires a couple of months, and that is a great burden on a patient. The second problem is that if a bone at a portion where the cavity is to be formed is thin or fragile, an implant surgery itself is impossible.
As a method for performing an implant treatment for a thin bone or a fragile bone, bone grafting can be performed. In the bone grafting, a block-state bone sampled from an iliac bone (hip bone) or the like is grafted at a portion of the bone where the implant treatment is to be performed, and the bone is fixed by a screw, a pin and the like to prevent it from moving. After the bone grafting, when a bone tissue is grown to sufficient height and width, a cavity for the implant treatment is formed. However, the bone grafting methods also have many problems. First, an operation to take out a bone is required, and operation spots are increased, which increases a burden on a patient. Secondly, since an extremely long time is required till the bone is grown after the bone grafting, there is a problem that a period till cure is much longer in addition to a period for a usual implant treatment. Thirdly, there is a problem that because of immunity reaction from the bone tissue around the implant portion, the implanted bone might not adhere.
The inventor discloses a plurality of auxiliary tools used in an implant treatment in Japanese Patent Application No. 2006-247561. As these auxiliary tools, auxiliary tools provided with needle portions having various diameters of 0.3 mm or more and 1.4 mm or less, respectively, are disclosed. These auxiliary tools are used in a pretreatment for forming a cavity in which an implant is to be inserted. In the auxiliary tools described in Japanese Patent Application No. 2006-247561, first, the auxiliary tool with the thinnest needle portion is used. When the auxiliary tool with the thinnest needle portion is manually squeezed into a jawbone, a small cavity is formed. After that, by sequentially squeezing the auxiliary tools with thicker needle portions into the same spot in the jawbone, the diameter of the cavity can be gradually increased. By sequentially using the plurality of auxiliary tools, the pretreatment to form a cavity for implant provided with an intended diameter is eventually completed.
The method for forming a cavity in which an implant is to be inserted using the above auxiliary tool can reduce a burden on a patient since an impact applied to the jawbone of the patient is smaller as compared with the prior-art method using a drill or a method of hammering a bone chisel into the bone of the patient.
Also, the inventor discloses an implant provided with an oval sectional shape to be suitably inserted in a thin jawbone in Japanese Patent Application No. 2007-211063 published on Mar. 5, 2009. In Japanese Patent Application No. 2007-211063, a bone chisel suitably used to insert the oval implant is disclosed. This bone chisel has a thickness of a blade edge at 0.3 to 6.0 mm. This bone chisel has a perpendicular sectional shape of the blade edge in an arc shape toward the distal end of the blade edge.
The method using the above bone chisel can further reduce the burden on the patient since the impact applied on the patient's bone is smaller as compared with the prior-art method using a drill or the method of hammering in a bone chisel into the bone of the patient. However, only by using the above auxiliary tool or bone chisel, it is difficult to create a suitable cavity in which a widely used columnar implant is inserted. Thus, a method of inserting an implant with higher versatility and a smaller burden on a patient is in demand.